It is known that an elastomer component is added to a thermoplastic resin so as to improve flexibility and impact resistance of the thermoplastic resin. However, there are such problems that the addition of an elastomer component increases a melting viscosity and further lowers resistance of the thermoplastic resin to hydrolysis.
U.S. Pat. No. 5,900,471 describes addition of polyetheramide block copolymer to a polyamide resin. In this patent, the polyetheramide has polyether segments containing an ethylene oxide block of the following formula:—(OCH(CH3)CH2)a(OCH2CH2)b(OCH2CH2CH2CH2)c—[in the formula, each of a, b and c is in the range of 0 to 1 and a+b+c=1].
There is also known addition of polyetheresteramide to a thermoplastic resin such as a polyamide resin.